Class Ember.CollectionView

Module: ember
Since: vEmber 0.9

Ember.CollectionView is an Ember.View descendent responsible for managing a collection (an array or array-like object) by maintaining a child view object and associated DOM representation for each item in the array and ensuring that child views and their associated rendered HTML are updated when items in the array are added, removed, or replaced.

Setting content

The managed collection of objects is referenced as the Ember.CollectionView instance's content property.

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someItemsView = Ember.CollectionView.create({
  content: ['A', 'B','C']
})

The view for each item in the collection will have its content property set to the item.

Specifying itemViewClass

By default the view class for each item in the managed collection will be an instance of Ember.View. You can supply a different class by setting the CollectionView's itemViewClass property.

Given an empty <body> and the following code:

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someItemsView = Ember.CollectionView.create({
  classNames: ['a-collection'],
  content: ['A','B','C'],
  itemViewClass: Ember.View.extend({
    template: Ember.Handlebars.compile("the letter: {{view.content}}")
  })
});

someItemsView.appendTo('body');

Will result in the following HTML structure

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<div class="ember-view a-collection">
  <div class="ember-view">the letter: A</div>
  <div class="ember-view">the letter: B</div>
  <div class="ember-view">the letter: C</div>
</div>

Automatic matching of parent/child tagNames

Setting the tagName property of a CollectionView to any of "ul", "ol", "table", "thead", "tbody", "tfoot", "tr", or "select" will result in the item views receiving an appropriately matched tagName property.

Given an empty <body> and the following code:

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anUndorderedListView = Ember.CollectionView.create({
  tagName: 'ul',
  content: ['A','B','C'],
  itemViewClass: Ember.View.extend({
    template: Ember.Handlebars.compile("the letter: {{view.content}}")
  })
});

anUndorderedListView.appendTo('body');

Will result in the following HTML structure

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<ul class="ember-view a-collection">
  <li class="ember-view">the letter: A</li>
  <li class="ember-view">the letter: B</li>
  <li class="ember-view">the letter: C</li>
</ul>

Additional tagName pairs can be provided by adding to Ember.CollectionView.CONTAINER_MAP

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Ember.CollectionView.CONTAINER_MAP['article'] = 'section'

Programatic creation of child views

For cases where additional customization beyond the use of a single itemViewClass or tagName matching is required CollectionView's createChildView method can be overidden:

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CustomCollectionView = Ember.CollectionView.extend({
  createChildView: function(viewClass, attrs) {
    if (attrs.content.kind == 'album') {
      viewClass = App.AlbumView;
    } else {
      viewClass = App.SongView;
    }
    return this._super(viewClass, attrs);
  }
});

Empty View

You can provide an Ember.View subclass to the Ember.CollectionView instance as its emptyView property. If the content property of a CollectionView is set to null or an empty array, an instance of this view will be the CollectionViews only child.

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aListWithNothing = Ember.CollectionView.create({
  classNames: ['nothing']
  content: null,
  emptyView: Ember.View.extend({
    template: Ember.Handlebars.compile("The collection is empty")
  })
});

aListWithNothing.appendTo('body');

Will result in the following HTML structure

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<div class="ember-view nothing">
  <div class="ember-view">
    The collection is empty
  </div>
</div>

Adding and Removing items

The childViews property of a CollectionView should not be directly manipulated. Instead, add, remove, replace items from its content property. This will trigger appropriate changes to its rendered HTML.